(1) Field of the Invention
The subject invention relates to a shock-absorbing assembly for use in a suspension system for a wheel of an automotive vehicle. Shock absorbers are utilized in automobiles to interconnect the wheel suspension assembly and the vehicle structure to absorb shocks as the wheels move in response to uneven terrain relative to the vehicle structure.
(2) Description of the Prior Art
Known assemblies include a shock assembly interconnecting the wheel and the vehicle structure with a rod in telescoping relationship with a shock-absorbing unit and attached to the vehicle structure with the shock-absorbing unit attached to the wheel assembly. In one such assembly, to which the instant invention relates, the shock-absorbing unit presents a shoulder surrounding the rod where the rod extends from the shock-absorbing unit with the other end of the rod attached to the vehicle structure. Additionally, an energy absorber is disposed about the upper end of the rod adjacent the vehicle structure to absorb energy in the event of a very severe shock where the shoulder on the shock absorber unit would approach the vehicle structure. Such an energy absorber has taken the form of a block of compressible material made of a plastic such as urethane or the like. The problem with the energy absorbers that have been utilized in such a system to date is that they have not been able to withstand rapid impacts at a variety of strains without significant deterioration over the life of the energy absorber. The energy absorbers known in the past have not always provided the desired combination of softness versus stiffness in proportion to the amount of compression or energy absorption of the energy-absorbing unit. Other problems which have been experienced are the cracking or tearing in the impact area of the energy absorber. In one unit a circular metal insert embedded within the energy absorber is set to react between the compressible material and the vehicle structure and surrounds the rod of the energy-absorbing unit but has a cylindrical portion disposed in spaced relationship to the rod whereby the energy-abosorbing material may be compressed sufficiently to be extruded through the annular space between the rod and the cylindrical portion of the insert.